As a result of traditional selective breeding methods, milk production in dairy cows far exceeds the requirements of the newborn calf. Because of udder size, position, and anatomic configuration for rapid removal of large volumes of milk, the mammary glands of dairy cows are especially prone to injury and infection. In particular, mastitis, an infection of the mammary gland, is common in milking dairy cows.
Clinically, mastitis typically produces heat, swelling, tenderness and possible deformation of the udder. Although the milk from a mastitic udder is generally safe for human consumption, a major concern is the cost to producers. Mastitis causes a decrease in the amount and quality of milk produced by the infected cow. With decreased quality, the price obtained for the milk likewise decreases. Certain organisms associated with some mastitis can lead to a cow's death, e.g., Escherichia coli.
Mastitis is typically caused by bacteria, such as Streptococcus agalactiae and Staphylococcus aureus which enter the teat through the teat orifice. These bacteria account for about 90 percent of all udder infections.
Typically after milking, a drop of milk remains on the tip of the teat, which can serve as a nidus for bacterial growth. Also, the teat canal is relaxed or dilated from the vacuum applied by the milking machine. The bacteria can then migrate through the teat orifice and into the internal teat cistern to cause inflammation and blockages.
The mastitis causing bacteria can be spread among cows by contaminated milking units or machines, by cow to cow contact, or can be transferred by milking personnel having contaminated hands. General housing conditions, such as stall size, ventilation, bedding material, and access to pasture are also known to have an impact on mastitis spread.
Systemic and local antibiotic administration is a proven method of mastitis treatment and prevention. Intramammary administration of antibiotics during non-lactating periods, known as dry cow therapy, is an established method for mastitis prevention when a cow is not lactating. For cows that are lactating, teat dips have long been used as a preventative for mastitis. Post milking teat dipping is considered to be the single most important factor in mastitis prevention. Teat dips can function by providing a physical barrier to bacterial entry through the teat orifice. Additionally, bacteria that may be present can be killed by antibacterial ingredients of some teat dips. Typically, the procedure of applying teat dip includes filling a cup or other suitable container with the dip formulation and dipping the teat therein. An aerosol spray generally may include the same or a slightly modified composition of the liquid dip and is sprayed on to the teat. The aerosol spray generally functions in the same manner as dips, with the exception that the aerosol can have a chilling effect on the teat, causing the sphincter muscle and teat orifice to contract, providing a further obstacle to prevent bacterial entry. Sometimes, a teat dip is applied with a pump sprayer.
Known active ingredients for teat dips include chlorine, iodine, in particular an iodophor, and chlorhexidine acetate and chlorhexidine gluconate. Some dip formulations have been developed which combine the desired germicidal or antibacterial properties of the active ingredients with suitable softeners or emollients, such as glycerin.
Although these well known and commercially available teat dips do have a beneficial effect on preventing the spread of mastitis there is a continuing need for improved compositions and systems for treating and preventing mastitis.